CLIMATE DRIVERS IN QUEENSLAND
In Queensland, Ridgy patrols the pressure pattern over southern areas. In winter in the south, he lets through cold, wet fronts, and in the north lets trade winds and their showers get going. In summer in the north, Ridgy helps bring on the monsoon, and leaves the south fine and dry.
Enso herds moisture from the Pacific Ocean towards Queensland. When there’s an El Nino, he causes less rainfall and fewer tropical cyclones. During La Ninas, he chases greater amounts of moist tropical air across Australia and causes more tropical cyclones.
Mojo loves to mess around in tropical areas – he can influence when the monsoon starts, and is most active from October to April.
Eastie scampers along the south-east coast of Australia, can go into action overnight, and his favourite seasons are autumn and winter. He can cause strong winds, heavy rains and lots of rough weather.
Indy can sometimes herd moisture across from the Indian Ocean to parts of the state in winter-spring, depending on whether he’s feeling positive or negative.
Sam can come to play in Queensland – sometimes bringing some cold wintery weather from the south affecting rainfall in winter, and sometimes gets working in spring and summer to bring more rainfall to south-eastern parts of the state.
FUTURE CLIMATE IN QUEENSLAND
Queensland’s climate in the decades ahead will be different from what it was in the past. We can expect changes in: temperature, extreme temperatures, humidity, wind speed, cyclones, rainfall, drought and extreme rainfall.
You will need to modify your farming practices to manage the risks presented by the change in climate. The vulnerability to climate change varies across Queensland and across agricultural sectors.
General threats for agriculture include:
- decline in productivity due to increased drought
- crop yields benefiting from warmer conditions and higher carbon dioxide levels but vulnerable to reduced rainfall
- greater exposure of stock and crops to heat-related stress and disease
- less winter chilling for fruit and nuts
- southern migration of some pests
- potential increase in the distribution and abundance of some exotic weeds
Temperature projections for Queensland indicate continued warming over the coming decades.
The projection is for a 1.0°C increase over 1990 climate by 2030 in coastal Queensland, and for a 1.5°C increase in inland Queensland. Under a low greenhouse gas emission scenario (best case), projection is for a 2.0°C increase over 1990 climate by 2070, and under a high greenhouse gas emission scenario (worst case), a 4.0°C increase is projected.
Slightly less warming is expected along the coast than in the rest of Queensland. Spring and autumn are expected to be warmer in line with the projected average increase. Summer is likely to be warmer by slightly more than the average projected increase. Winter is likely to be warmer by slightly less than the average projected increase.
Scientists have more confidence in the projections for mean temperature than in those for rainfall. They have more confidence in the projections for 2030 than in those for 2070.
We can expect more very hot days and nights. By 2070, under a high greenhouse gas emission scenario, the number of days per year above 35°C is likely to double. We can expect less frosts and less very cold days and nights.
Inland, we can expect small decreases in relative humidity. Along the coast, there is likely to be little change.
In south-east Queensland, we can expect small increases in average wind speed.
The intensity of tropical cyclones is expected to increase.
During winter and spring, we can expect a drying trend for central and southern Queensland. Summer and autumn rainfall changes are less certain. For the far north, projections are mixed, so the best estimate is for little change.
The projection is for a 5% decrease in annual rainfall in 2030 relative to the 1990 climate. Under a low greenhouse gas emission scenario (best case), projection is for a 10% decrease in annual rainfall by 2070 when compared to 1990, and under a high greenhouse gas emission scenario (worst case), a 20% decrease is projected.
Scientists have more confidence in the projections for temperature than in those for rainfall. They have more confidence in the projections for 2030 than in those for 2070.
Potential evapotranspiration is expected to increase over Queensland. Evapotranspiration is the combination of evaporation from soil and water surfaces, and transpiration from vegetation. When these changes are combined with the projected declines in rainfall, an increase in aridity and drought occurrence is likely.
Climate projections show an increase in daily precipitation intensity and an increase in the number of dry days. This suggests that Queensland’s rainfall patterns will have longer dry spells interrupted by heavier rainfall events.
QUEENSLAND CLIMATE EXPERTS
QUEENSLAND CASE STUDIES